Split-bolt latch



June-25, 1929. w. R. SCHLAGE 1,718,711

SPLIT BOLT LATCH Filed Aug. 10, 1927 INVEN TOR.

TT ORNEYS.

Patented June 25, 1929.

UNITED STATES PATENT OFFICE.

\ WALTER R. SCHLAGE, 0F SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO SCHLAGE LOCK COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

SPLIT-BOLT LATCH.

Application led August 10, 1927. Serial No. 211,915.

rlhis invention relates to a split bolt latch which is particularly adapted for use in hotels and the like where adjoining rooms are provided with inter-com1nunicating doors.

The object of the present invention is to generally improve and simplify the construction and operation of latches of the character described, to provide a latch which may be readily and quickly fitted and installed in a door, to provide a split bolt latch which permits locking of the door from both or either side thereof, to provide means whereby the positions of the split bolt when in locked or unlocked position are visibly indicated, and further to provide means whereby both or either section of the split bolt is dogged against retraction or depression by means of a immy tool or the like.

rllhe invention is shown by way of illustration in the accompanying drawings, in which Fig. 1 is a plan view of the latch, showing it installed in a door, said view showing the door in section, and also a part of the latch mechanism in section.

Fig. 2 is a partial side elevation of the outer end of the latch housing showing one of the bolts projected, said view being par tially in section.

Fig. 3 is a perspective View of one of the bolts.

Fig. 4 is a perspective view of the latch housing and the bolts, said view being partially broken away and being shown partially in section.

Fig. 5 is a perspective view of the end plate of the housing.

Fig. 6 is a perspective view of one of the roll back pins and the member supporting the same.

Fig. 7 is a perspective view of one-half of the latch housing.

Fig. 8 is a cross section taken on the line sns 'of Fig. 1.

Fig. 9 is a central vertical longitudinal section through th f housing showing one of the bolts in projec ed position.

Fig. 10 is a cross section of the latch housing and the slide plates, taken on the line 10-10 of Fig. 1.

Referring to the drawings in detail, and particularly Figs. 1, 2, 3, 4, 5, 6 and 7, A indicates in general a latch housing which, in this instance, is split longitudinally to form two half sections such as indicated at 2 and 3.

These half sections are substantially identical, and are best illustrated in Fig. 7. The

half section of the housing is substantially channel-shaped in cross section. It consists of a side wall plate 4, top and bottom plates 5-5 and perforated end lugs 6 6. The top and bottom walls are enlarged at the points indicated at 7-7, and the bearing member is pressed out of the side wall section 4, as indicated at 8. The half section is open at both ends, as indicated at 9 and 10, a plurality of lugs being formed on the inner end, as indicated at 11 and 12, for purposes hereinafter to be described. The side wall section 4 is also provided with a pair of recesses, as indicated at 14 and 14a. The function of these recesses will hereinafter be described. Slidably mounted between the top and bottom plates 5 5 of the two housing sections are a pair of bolts generally indicated at 15 and 16. These bolts are identical in construction, and are best shown in Figs. 3 and 4. One end of each bolt has a cross slot formed therein, as indicated at 17, and each bolt has a hole or recess drilled therein, as indicated at 18. Springs 19 are inserted in these holes, and a detent or latch in the form of a ball, such as indicated at 20, is placed on top of each spring. These detents are projected into the recesses 14 or 14 as the bolts are projected or retracted, and as such yieldingly retain the bolts in retracted or projected position.

By referring to Fig. 6 it will be noted that a retractor or roll-back is shown. It consists of a circular plate 21 which is formed on the hub member 22. Secured on the face of the plate 21 opposite the hub is a pin 23, and formed in the hub and in the plate 21 is a square-shaped opening 24. The roll-back members are journalled in the respective bearings indicated at 8, and the roll-back members are spaced apart a sufficient distance to permit the insertion of a pair of slide plates, generally indicated at 25, there being one slide plate for each bolt. The slide plates are best illustrated in Fig. 4. One end of each plate is enlarged, as indicated at 25, so as to be engaged and guided by the enlarged top and bottom wall sections 7 7. A slot 26 is formed on each plate which is adapted to re'- ceive the adjacent roll-back pins indicated at 23, each slot being so shaped as to form an overhanging lug 27, the function of which will hereinafter be described. Each slide plate is provided with a forwardly project- I ing arm 28, on the outer end of which is formed a finger 29 which projects into the cross slot 17 of an adjacent bolt. An interlock is in this manner formed between each slide plate and bolt, and the bolts are retracted or projected by the slide plates when the rollback members shown in Fig. 6 are rotated. The roll-back members are rotated by means 'of spindles, generally indicated at 30. These spindles are journalled in escutcheon plates such as shown at 31, and each spindle carries a thumb latch such as shown at 32. There are two spindles, one for each thumb latch, the spindles being just suiiiciently long to project into the roll-back members so as to rotate the same when the thumb latches are rotated. i

In actual operation the latch mechanism is assembled by inserting the springs 19 and the detente 20 in the respective bolts. The bolts are placed in one of the housing sections, as shown in Fig. 4. The roll-back members, such as shown in Fig. 6, are inserted in the bearings 8, the slide plates 25 are placed in position and the two lhalves of the latch housing are then placed face to face so as to enclose the bolts, the detents, the slide plates and the rollback members. The two sections of the latch housing are then permanently secured with relation to each other by first applying an end plate 35, such as shown in Figs. 4 and 5, and by bending over the lugs 11, and secondly by applying an outer end plate 36 which is drilled or perforated at the points 37, these perforations being in alignment with the end lugs 6 6 of the housing sections which overlap each other when the housing sections are assembled. The holes 37 are preferably punched so as to force the metal through the perforated lugs 6, as shown at 38 in Fig. 2, and the metal is then spun or clinched over behind the lugs 6, as shown at 39, to permanently secure the parts with relation to each other. This completes the assembly of the latch housing `and the mechanism carried thereby. The only other mechanism required are the thumb latches carrying the spindles 30 which are journalled in the escutcheon plates 31.. These are not placed in position until the main latch housing is inserted in the door. This is accomplished as follows: when it is desired to apply a split bolt latch, as here illustrated, to a door, it is merely necessary to employ an ordinary brace and bit and to drill a hole through the edge of the door as indicated at B in Fig. 1, and then to drill a second hole at right angles thereto, completely through the door, as shown at C. `When these holes have been drilled the latch housing generally shown in Fig. 1 is inserted end-wise into the opening B and it is here permanently securedby inserting two screws, such as shown at 45, through the outer end plate 36. The escutcheon plates 31 carrying the thumb latches and the spindles are then applied by inserting them through the holes C drilled through the opposite faces of the door. iVhen inserted they assume the position shown in Fig. 1, and they are there secured by screws such as indicated at i6, see Fig. 10. iVhen so assembled the spindles project into the central square openings 2l formed in the roll-back members, and it is thus only necessary to rotate either ol the thumb latches to project or retract the bolts. One thumb latch actuates one bolt while the other thumb latch actuates the other, and as they are disposed on opposite sides of the door itis obvious that it is possible to lock the door from either side.

One of the important features of the present invention is the provision of means for dogging the bolts against retraction when projected. That is, it is a comparatively simple matter for a burglar or other unauthorized person to open a door by merely inserting a jimmy or other tool between the door and the bolt, and thereby depressing or retracting the same. Such depression of the bolts 15 and 16 is prevented in the present instance by providing the lug 27, see Fig. 9. This luef slightly overhangs the roll-back pin 23, so that when pressure is applied to the outer end of one bolt or either of them a downward pressure is exerted by the lug or lugs 27 on the roll-back pin or pins at the point above the center' of the same. Such downward pressure on the pins prevents them from moving upwardly in the slots 26' and rotation of the roll-back'members and the spindles is accordingly prevented, and when such rotation is prevented it is more or less obvious that the bolts cannot be rctracted.

Another important feature of the invention is the provision of a spindle actuated rollback which merely requires a O rotation of the spindle and roll-back to insure complete projection or retraction of the bolt. That is, the pin 23 0n the roll-back member assumes the full line position shown in Fig. 9 when the bolt is completely projected, and it assumes the dotted line position shown in Fig. 9 when completely retracted. This change of position merely requires a 900 rotation or quarter-revolution of the spindle and thumb latch, and as such permits visible indication of the position of one bolt or either of them. That is, the thumb .latches are so positioned on the spindles that they assume a vertical position such as shown on the lower side of Fig. 1 when the bolt is retracted, and a horizontal position such as shown on the upper side of Fig. 1 when the bolt is projected. Thus by the position of one thumb latch or either of them it is possible to determine whether the bolts are projected or retracted.

Other important features of the present invention are simplicity of construction and assembly .and the ease with which a. latching mechanism of this character may be installed in a door. While twobolts are illustrated in the present instance, it should be obvious that a single bolt may be employed if desired, as two complete setsof bolts and operating mechanisms operable independently of each other are shown in the present instance. It will accordingly, only be necessary to narrow the housing so that proper space will be provided for the guidance and retention of a single bolt, slide plate and roll-back member it one bolt is desired.

llVhile other features of the invention are more or less specifically described and indicated, I wish it understood that various changes may be resorted to within the scope of the appended claims. Similarly, that the materials and finish of the several parts employed may be such as experience or judgment of the manufacturer may dictate or varying conditions may demand.

Having thus described my invention, what l claim and desire to secure by Letters Patent is:

l. A device of the character described comprising an elongated housing, a bolt slidably mounted therein, said bolt having an arcuated slot formed in one edge thereof, a spindle projecting through one side of the housing, and a crank-like roll-back pin actuated by the spindle, said pin projecting into the arcuated slot of the bolt and adapted to project or retract the bolt when the spindle is rotated.

2. A device of the character described comprising an elongated housing, a bolt slidably mounted therein, said bolt having an arcuated slot formed in one edge thereof, a spindle projecting through one side of the housing, a crank-like roll-back pin actuated by the spindle, said pin projecting into the arcuated slot of the bolt and adapted to project or retract the bolt when the spindle is rotated, and a lug on the bolt forming one side' of the arc'uated slot engageable with the roll-back pin and partly overlying the pin to secure the bolt against retraction except by rotation of the spindle and the roll-back pin actuated thereby. j

3. A device ofthe character describedcom- 'prising an elongated housing, a bolt slidably mounted therein, a slide plate slidably mounted in the housing, an interlocking connection formed between the inner end of the bolt and the slide plate, said slide plate having an arcuated slot formed in one edge thereof, a plate having a hub formed thereon and journalled vin the housing, a crank pin on the plate and projecting into the arcuated slot ormed in the slidin plate, a spindle projecting through one side of the housing, said spindle also projecting through the hub member which carries the plate and the crank pin so that rotation of the spindle will rotate the hub member, the plate and the crank pin and thereby impart longitudinal movement to the sliding plate and the bolt, and means on the sliding plate and engageable with the crank pin to dogr the spindle, the hub member, the plate and the crank pin against rotation when endwise pressure is exerted on the bolt and sliding plate when these assume a projected position.

4. A device of the character described comprising an elongated housing, a bolt slidably mounted therein, a slide plate slidably mounted in the housing, an interlocking connection formed between the inner end of the bolt and the slide plate, said slide plate having a slot formed therein, a plate having a hub formed thereon and journalled in the housing, a crank pin on the plate and projecting into the slot formed in the sliding plate, a spindle projecting through one side of the housing, said spindle also projecting through the hub member which carries the plate and the crank pin so that rotation of the spindle will rotate the hub member, the plate and the crank pin and thereby impart longitudinal movement. to the sliding plate and the bolt, and a lug carried by the sliding plate and engageable with the crank pin, said lug securing the spindle and the members carried thereby against rotation when endwise pressure is exerted on the bolt when it assumes a projected position.

5. In a device of the character described, an elongated housing, a pair of intcrspaced plates journalled one on each side of the housing, a crank pin on each plate, means for rotating said plates to swing the crank pins through an arcular path, a pair of sliding plates interposed between the rotating plates, each sliding plate having an arcuated slot formed on one edge thereof vinto which the adjacent crank pin projects and whereby sliding movement is imparted to the sliding plates when the rotating lates are rotated, and a pair of bolts slidab y mounted in the housing and forming extensions of the respective lsliding plates.

WALTER n. scHLAGE. 

